Photographic developing apparatus



' May 16, 1944.

L. A. WILDMAN PHOTOGRAPHIG DEVELOPING APPARATUS Original Filed June 9, 1942 Patented May 16, 1944 iJNlTED STATES PATENT OFFICE Griginal application June 9, 1942, Serial No. 446,370. Divided and this application May 20, 1943, Serial No. 487,757

2 Claims.

This invention relates to photographic developing, and more particularly toapparatus of this character designed for home or amateur use.

The present application is a division of my prior copending application, S. N. 446,370, filed June 9, 1942.

One object of the invention is to provide simple, motor-driven means for continuously rocking a developing tank of the conventional type, so as to agitate the liquid therein.

The invention is particularly applicable to tanks of the type in which a vertical shaft is provided, which shaft is ordinarily turned by hand. A further object of the invention is to provide improved means whereby such a shaft is automatically turned by the rocking of the tank.

A still further object of the invention is to provide a construction in which the tank itself is wholly unattached to and removable from the rocking mechanism.

In order that the invention may be readily understood, reference is had to the accompanying drawing forming part of this specification and in which- Fig. 1 is a plan view of my improved apparatus;

Fig. 2 is a side elevation thereof; and

Fig. 3 is a fragmentary side elevation showing the tank removed from the holder.

Referring to the drawing in detail, my improved apparatus comprises a base l, preferably of elongated form, and which may conveniently consist of a wooden board or the like, supported on cleats l Secured to the base I are a pair of upstanding brackets 2, in which is journalled a transversely extending rock shaft 3.

Rigidly secured to this rock shaft between the supporting brackets 2 is an open pan or tray i, best shown in Fig. 3, in which a developing tank 5 of the usual form is adapted to fit or seat, so that the tray 4 serves as a holder for the tank. The tray comprises a flat bottom and a peripheral flange. It will be understood that the tank rests on the bottom of the tray with the peripheral flange loosely engaging the sides of the tank. Thus the tank is held in position in the tray or holder by gravity only, without being fastened therein, so that it is readily removable therefrom, as shown in Fig 3.

This tank may be of the type having a central upstanding shaft 6, which is normally adapted to be rotated by hand, for the purpose of moving the film with respect to the solution contained in the tank.

According to the present invention, I replace the usual hand operating means at the upper end of the shaft 6 by a spider 1 having radial arms, as shown in Fig. 1, which spider is ri idly secured to the shaft 6.

A pawl 8 pivoted at 9 to a supporting post Ill, secured to the base I, is arranged to ride upon and engage the arms of the spider l, as shown in Fig. 1.

Fixed to one end of the shaft 3 is a crank arm H (see Fig. 2) and this is connected by means of a pitman or link l2, with a crank 13, secured to the end of a shaft projecting from a gear box M. The gearing in this box is operatively connected to a small electric motor l5, so as to be driven thereby.

From the foregoing, it will be understood that as the motor l5 runs, the gearing in the box M will be driven and the crank l3 caused to turn, thus, by means of the link I2 and crank arm ll, oscillating the rock shaft 3 and with it the developing tank 5, thus efiectively I agitating the liquid in the tank. As the tank oscillates from one side'to the other, as indicated by broken lines in Fig. 2, the pawl 8, which extends in a direction generally parallel with the plane of oscillation successively engages the spokes or arms of the spider I, thus causing the spider to turn, step by step. It will be understood that the frictional resistance of the shaft is sufficient to hold it from turning backward as the pawl rides idly over the spider arms during movement of the tank in one direction. Thus the shaft 6 is caused to rotate, carrying the film with it, and in this way uniform contact of the liquid with all parts of the film is assured.

What I claim is:

1. Photographic developing apparatus com prising a tank having an upright shaft rotatably mounted therein, a holder in which the bottom of said tank is removably supported, a base on which said holder is pivotally mounted for oscillation about a horizontal axis, means on said base for continuously oscillating said holder and tank, and means operated by such oscillating movement for continuously rotating said shaft step'by step, in the same direction.

2. Photographic developing apparatus comprising a base, a developing tank having an upright shaft rotatably mounted therein, means on said base for rocking said tank about a horizontal axis, a spider rigidly secured to the upper end of said shaft, and a pawl pivotally supported by said base at a point above and laterally of said tank, said pawl extending parallel with the plane of oscillation of said tank and having its free and resting upon said spider, said free end being so formed as to ride over said spider when the latter is moving in one direction and to positively engage the spider when it is moving in the other direction, whereby the rocking movement of said tank serves to continuously rotate said spider and shaft, step-by-step.

LOYD A. WILDMAN. 

